Single-electron-capture cross section for medium- and high-velocity, highly charged ions colliding with atoms

Experimental cross sections for single-electron capture for medium- to high-energy, highly charged oxygen and gold ions colliding with helium atoms are presented. Simple estimates based on the classical cross sections introduced by Bohr and Lindhard for multiply charged ions are shown to lead to good first approximations of the absolute magnitude of the cross sections for any target atom. Furthermore, these estimates suggest a universal scaling of the capture cross sections with ion and target-atom parameters. The experimental results of this work as well as those obtained by other groups are shown to be in accordance with the suggested scaling laws, which are also supported by the results of the few more-refined theoretical treatments that have been published.